A light-emitting diode (LED), particularly a blue or ultraviolet (UV) LED having an emission wavelength of approximately 250 nm to 550 nm, is a high-brightness product using a GaN-based compound semiconductor such as GaN, GaAlN, InGaN, or InAlGaN. In addition, it is possible to form a high-quality full-color image by a method of combining red and green LEDs with a blue LED. For example, a technique of manufacturing a white LED by combining a blue or UV LED with a fluorescent material is known. Such LEDs are widely used as backlights for liquid crystal displays (LCDs) or as light.
Since light emitted from an LED has high linearity, it may be necessary to disperse the light in various directions. When the high-linear light is directly observed with the naked eye, the eyes may be very tired, and in some cases, may be damaged. To disperse the high-linear light, inorganic particles such as silica may be blended to an encapsulant of the LED, but the blended inorganic particles may precipitate due to density difference, or increase viscosity of a resin, thereby having an effect on processability. While it may be considered that light is scattered by blending polymer particles, since the polymer particles do not usually have sufficient heat resistance or light resistance, discoloration may be a problem when the particles are used for a long time.
As an LED encapsulant, an epoxy resin having high adhesive strength and excellent mechanical durability is widely used. However, the epoxy resin has a lower light transmittance in a blue light or UV ray region, and low light resistance. For example, Japanese Patent Application No. H11-274571, 2001-196151, and 2002-226551 present techniques for solving the above-described problems.